Here is the view of the back side of a FC-150 Pickup gas tank. You can see the corrosion at the bottom were dirt was trapped between the tank and the bed.
Bruce Hamilton recently took the bed off a FC-150 that he owns and sent me some pictures of the process and also some things that you could run into in the restoration of your FC-150 pickup. It's also kind of a guide of what to look out for when shopping for a FC to purchase. I hope to soon include a cab version of this for potential buyers to study before purchasing their new Forward Control vehicle. Many thanks for getting us this information Bruce.